This invention relates generally to a bifold door assembly and an improved hinge structure for joining the pivoted door to the guide door, and more particularly to a novel hinge structure which facilitates operation of the door and provides certain economic advantages with respect to fabrication of both the door and the hinge structure.
Bifold door structures are well known and typically include a pivoted door mounted proximate a vertical portion of the door frame and a guide door joined to the pivoted door by one or more hinge structures, and having the remote edge thereof confined for linear movement. The doors are normally mounted between a pair of parallel upper and lower guide tracks. In this regard, the pivoted door is pivotally mounted adjacent the door frame, generally proximate the upper and lower edges thereof, by pivot assemblies engaged in the respective guide tracks. That is to say, this door will merely pivot during opening and closing, with the edge adjacent the frame precluded against linear movement. The guide door is hingedly connected to the opposite edge of pivot door, with the guide door edge remote from said pivot door having pivot guide assemblies carried by the upper and lower edge portions, which assemblies are engaged in said guide tracks. As such, as the doors are opened, they will fold upon each other, in that the pivoted door merely pivots while the guided door is subjected to compound movement. More specifically, the guided door will pivot about the guide-pivot assemblies engaged in the tracks, however, the assemblies will slide along the track toward the pivoted door to produce the open condition. While the prior art hinge structures have generally been satisfactory in operation, certain problems have arisen in their use, and in the fabrication of the doors, as is discussed hereinafter.
Specifically, bifold type doors are generally mounted to open or fold outwardly of the space enclosed, such as a closet, cabinet, or the like. Hence, it is desirable for the fully opened bifold door structure to form an angle somewhat greater than 90.degree. with respect to the guide tracks when fully open, to provide maximum access to the closet or the like. A related problem is that of maintaining relatively smooth, non-binding operation of the track mounted slide portions of the guided door. As will be described more fully hereinbelow and with reference to the drawings, many prior art hinge structures tend to encourage, rather than reduce the tendency for the guide pins to bind in the track during operation of the bifold door structure. As will be described, opening of the door structure to an angle greater than 90.degree. serves to minimize this binding problem.
One prior art solution to the above problem as is illustrated in FIG. 3 and to be described, involves use of a standard type hinge wherein the hinge leaves are mounted to the rear face of the doors. While this arrangement will produce an open condition wherein the doors are positioned at an angle greater than 90.degree., other drawbacks result. More specifically, this door panel is normally predrilled to receive the pivot and pivot-guide hardware, respectively. However, the design of FIG. 3 requires that the pivoted door and guided door be drilled at different or non-symmetrical locations thus necessitating two different door panel designs. From a standpoint of economy of manufacture and assembly, such distinguishing of door panels is not desirable, since care must then be taken to assure that one of each type panel is included for each bifold door structure to be delivered to a customer, who normally effects assembly therein. Moreover, an installer must recognize the difference between the two door panels and take care to install them properly. In contrast, it is generally more desirable to provide identical door panels to minimize both the expense and difficulty of manufacture as well as of installation.
The problem of individual pre-drilling of the door panels can be overcome by use of a hinge mounted directly to the juxtaposed edge surfaces of the door, as shown in FIG. 2. With this arrangement, however, the doors cannot be opened beyond 90.degree., and as will be discussed, binding is a problem.
Accordingly, it is a general object of this invention to provide a new and improved hinge structure for a bifold type of door. Another object of this invention is to provide a hinge structure which allows opening of the door structure so as to form an angle greater than 90.degree. with its guide track to minimize building of the guides with respect to the guide track, yet does not require specialized fabrication of the door panels. Yet another object of this invention is to provide a hinge structure which does not require preassembly by the manufacturer of the respective leaf members, yet is relatively simple to install, thereby minimizing both the difficulty of installation and the cost of manufacture.
Briefly, the present invention contemplates attaining the above objectives, and others by the provision of a hinge structure which comprises a first leaf member including a generally planar mounting or leaf portion, with at least one open, U-shaped knuckle portion, and a second leaf member including a generally planar mounting or leaf portion, having a closed knuckle portion with at least one rod-like pin member extending axially outwardly therefrom. The pin member is disposed within the U-shaped, open knuckle portion of the first leaf member, and the first leaf member is mounted, such that the aligned knuckle portions are offset with respect to the interface of the door edges, with the door surface to which the first leaf is mounted cooperating with the open portion to confine the pin member and prevent lateral separation.
Other objects, features and advantages of this invention will be appreciated upon consideration of the following detailed descriptions, together with the accompanying drawings wherein like reference numerals are used throughout to designate like elements and components.